Field of the Disclosure
Aspects of the disclosure relate generally to electrical circuits, and more specifically, but not exclusively, to a signal interconnect that includes a high pass filter.
Description of Related Art
With the advancement of very large scale integration (VLSI) technology, inter-chip communication is expected to exceed 20 GHz. The design of an inter-chip interconnect that operates at high signaling rates may compensate for high losses, latency, and parasitic effects that occur at these signaling rates. In addition, it is desirable to keep power consumption low even at these high signaling rates.
Some high speed transmission line designs use active pre-emphasis and equalization circuits at the drivers and the receivers. However, active circuits consume a significant amount of power.
Passive compensation is one potential approach to achieve the goal of high speed and low power. With a passive approach (e.g., using passive and linear elements), active components conventionally used in a transmission line design are eliminated. Thus, the compensation circuitry will consume much less power. In one passive compensation technique, a resistive terminator is used to maximize the height of the eye-pattern of the signal at the receiver. In another passive compensation technique, a discrete set of shunt conductance is employed to match the distortionless condition of the Heaviside function. In another passive compensation technique, a serial resistor replaces the resistive terminator for scenarios where the delay time of the transmission line is shorter than the half bit period. Hence, this latter technique is limited by the length of the wire and the wave length of the signal.
In general, inter-chip parasitic effects make these schemes difficult to implement. Digital signals have wide band frequency components. Consequently, it is desirable for an interconnect to tolerate a wide band working frequency. In view of the above, there is a need for a passive compensation scheme that can reduce jitter effectively and still have a good receive signal eye-pattern at very high frequencies.